The present invention relates generally to human joint replacement surgery, and particularly to a method and system that enable an orthopedic surgeon to monitor impaction data, such as vibration data, generated during impaction of the femoral component of a hip prosthesis into a femur and determine maximal femoral component interference fit and prosthetic stability to prevent femoral fractures during the impaction process.
Total hip replacement, or hip arthroplasty, is one of the most consistently successful surgical procedures in medicine. Recently, new minimally invasive surgical techniques in hip arthroplasty that offer numerous advantages over standard surgical approaches have been introduced. These purported advantages include shorter hospital stays, more rapid rehabilitation and recovery, less blood loss, and diminished postoperative pain.
However, there are some potential drawbacks to minimally invasive surgical techniques. Although such techniques require smaller incisions compared to conventional techniques, the smaller incisions diminish the surgeon's ability to adequately visualize the entire proximal femur. This decrease in visual ability places additional emphasis on the surgeon's auditory and tactile senses in determining the optimal interference fit, or seating, of the implant within the geometry of the proximal femur, which is required for maximal implant stability.
With emerging minimally invasive surgical techniques in total hip arthroplasty, there is anecdotal evidence of an increase in periprosthetic fractures associated with insertion of the femoral component. This is likely the result of diminished visibility, auditory and tactile feedback for the surgeon operating through smaller incisions. Intraoperative periprosthetic femur fractures may occur if the implant is impacted past the point of maximal interference fit, subjecting the cortical bone of the proximal femur to excessive hoop stresses. Such fractures, especially if unrecognized, decrease the mechanical stability of the femoral component and may increase the risk of implant failure that is likely a result of diminished early bone ingrowth from fracture-induced instability and micromotion.